Saliva is an important body fluid and hyposecretion of saliva impairs various oral functions. To understand the mechanisms of salivary gland dysfunction and recovery, we established a system for primary culture of parotid acinar cells. Previous work reported that the isolation from the parotid glands and culture of acinar cells altered gene expression, leading to dedifferentiation. When the Src kinase inhibitor PP1 was added during culture, changes in gene expression were suppressed, and the acinar cell properties were maintained for a longer period. In this study, we compared microRNA (miRNA) expression profiles of cells isolated in the absence and presence of PP1, and cells culture for 1 day in the absence and presence of PP1. The effect of PP1 on changes in miRNA expression was compared with the changes in miRNA levels during the 1-day culture. We found that the changes in miRNA levels due to 1-day culture were partially suppressed by the addition of PP1. KEGG pathway analysis was performed using five miRNAs that were altered by 1-day culture and whose changes were reversed by the addition of PP1. The analysis suggested pathways related to the TGF-ϐ signaling, cell cycle, and regulation of stem cell pluripotency. These results imply a role of miRNAs in the injury response and tissue repair of the salivary glands.
Fujita-Yoshigaki et al. (Thu,) studied this question.